Yarn weight chart

Weight	Yarn types (CYC)	Knit gauge, stitches per 4"¹	Needle	Crochet gauge, sc per 4"¹	Hook	WPI
0 Lace	Fingering 10-count crochet thread	33–40²	1.5–2.25 mm US 000–1	32–42 double crochets²	Steel³ 1.6–1.4 mm (6, 7, 8), regular 2.25 mm B-1	30-40+
1 Super Fine	Sock, Fingering, Baby	27–32	2.25–3.25 mm US 1 to 3	21–32	2.25–3.5 mm B-1 to E-4	14-30
2 Fine	Sport, Baby	23–26	3.25–3.75 mm US 3 to 5	16–20	3.5–4.5 mm E-4 to 7	12-18
3 Light	DK, Light Worsted	21–24	3.75–4.5 mm US 5 to 7	12–17	4.5–5.5 mm 7 to I-9	11-15
4 Medium	Worsted, Afghan, Aran	16–20	4.5–5.5 mm US 7 to 9	11–14	5.5–6.5 mm I-9 to K-10½	9-12
5 Bulky	Chunky, Craft, Rug	12–15	5.5–8 mm US 9 to 11	8–11	6.5–9 mm K-10½ to M-13	6-9
6 Super Bulky	Super Bulky, Roving	7–11	8–12.75 mm US 11 to 17	7–9	9–15 mm M-13 to Q	5-6
7 Jumbo	Jumbo, Roving	6 and fewer	12.75 mm and larger US 17 and larger	6 and fewer	15 mm and larger Q and larger	1-4

A yarn’s weight, in the Craft Yarn Council’s (CYC) sense, is its thickness. CYC’s label symbols designate “weights (thicknesses)” with a number from 0, the finest, to 7, the thickest. Gauge is how many stitches fit in 4", and a swatch is the small test square you knit or crochet to measure it.

Have a label? Type its gauge, its needle or hook size, or both into “Match my label”. No label? Start with how to tell yarn weight.

How to use the yarn weight chart

Pick the columns: Both, Knitting or Crochet. The yarn types and WPI (wraps per inch) columns always show.
Fill in “Match my label”. Say which craft the label’s gauge is for. That also decides whether your mm is read as a needle or a hook, so give the size for the same craft. Then type the gauge, the size in mm, or both. Need the mm for a US size? Use the knitting needle size chart or the crochet hook size chart.
Read the answer. Matching rows light up. One entry shows every weight it fits; with both, only the weights that fit both. Three made-up labels:
- Knitting, 24 stitches and a 3.5 mm needle: the gauge alone fits 2 Fine and 3 Light, the needle only 2 Fine, so the answer is 2 Fine.
- Knitting, 21 stitches and a 3.5 mm needle: the gauge says 3 Light and the needle 2 Fine, so there’s no match.
- Crochet, 12 single crochet (UK double crochet) and a 6 mm hook: the gauge fits 3 Light and 4 Medium, the hook only 4 Medium, so it’s 4 Medium.
Convert the label: type its yards and grams per skein (the wound bundle a yarn is sold in).

Yarn weights 0 to 7: CYC’s categories

The higher the number, the fewer stitches per 4": CYC lists 33 to 40 knit stitches for 0 Lace (see note ²) and 6 or fewer for 7 Jumbo. In CYC’s yarn types, for example, DK, short for double knitting, is a 3 Light type, and worsted a 4 Medium type, one category thicker. CYC has announced a size 8, but its table still stops at 7. A few yarn-type names appear in two rows, which the guide linked above sorts out.

The ranges are CYC’s most common gauges and sizes, not limits: note ¹ under the chart calls them guidelines only. Knit gauge is counted in stockinette (knit rows on the right side, purl rows on the wrong side), crochet gauge in single crochet.

0 Lace is the exception: CYC counts its crochet gauge in double crochets (UK treble crochet), so a single crochet count never matches it; note ² covers lace gauge. A hook can still match 0 Lace: a steel hook (a metal hook CYC says is generally used with lace yarn and crochet thread) in its hook cell’s range, or a regular 2.25 mm (B-1), which also fits 1 Super Fine.

Where the knitting and crochet ranges overlap

Knitting gauges overlap only at 23 and 24 stitches. Crochet overlaps in more places: 8 and 9, 11, 12 to 14, and 16 and 17 single crochet each fit two weights. So a crochet gauge alone often gives two answers, and the hook size can narrow it, as in the crochet example above. For needle and hook sizes on the edge of two ranges, see the size charts linked in step 2.

The WPI column

WPI counts how many wraps of a yarn, laid side by side around a pencil, fit in 1". The note under the chart gives CYC’s sources and says WPI is subjective. “Match my label” takes no WPI, so read it off the column; the yarn weight guide shows how to count wraps and settle a tie. Instead of a pencil you can use an acrylic WPI ruler ad ; any markings on it are the maker’s, not CYC’s.

Comparing yarn weights to substitute a yarn

Look up both yarns in the chart, or put each label into “Match my label”. Lion Brand’s blog says: “You will have much better luck substituting yarns of the same weight category.” Purl Soho, a yarn shop, calls a yarn of about the same weight “a good place to start”. It then suggests comparing yardage, warning that fiber content and yarn structure affect yardage a lot: two 100% wools with the same yards per 100 g have a decent chance of a similar gauge, a cotton much less.

The label converter puts skeins of different sizes on one footing: it opens at 220 yd per 100 g, and a 50 g skein of 109 yd works out to 218 yd per 100 g. How many yards in a skein converts six real labels.

Then swatch to the pattern’s gauge, not the gauge on the suggested yarn’s label, Purl Soho says, and wash the swatch the way you’ll wash the finished piece. A needle gauge with a stitch-gauge ruler ad checks stitch and row gauge. With your swatch’s stitch count, the gauge calculator works out stitch counts; weigh the swatch too, and the yarn calculator works out the yardage.

FAQs

Can I use DK instead of worsted?

In knitting, not as a straight swap: CYC’s gauge ranges for DK (3 Light, 21–24 stitches per 4") and worsted (4 Medium, 16–20) share no stitch count. Swatch first, as the substitution section above explains.

What yarn weight is 4 ply?

CYC’s list of yarn types doesn’t include “4 ply” (a ply is one of the strands spun together into a yarn), so the name alone doesn’t place a yarn in the chart. Use the label’s gauge and needle or hook size in “Match my label”.

Is yarn weight how heavy the skein is?

Not in CYC’s sense. The grams or ounces on a label tell you how much the yarn “physically weighs”, WEBS, a yarn shop, explains. The category comes from the weight symbol, or the gauge and needle or hook size.